Migrating to release 3.0

DITA-OT 3.0 adds support for Markdown, normalized DITA output, and the alternative
authoring formats proposed for Lightweight DITA. The map-first preprocessing approach provides a modern
alternative to the default preprocess operation.

Note: This topic provides a summary of changes in DITA-OT 3.0 that may require modifications to custom stylesheets
or plug-ins. For more information on changes in this release, see the
DITA-OT 3.0 Release Notes.

Legacy plug-ins removed

DITA-OT 3.0 no longer includes the following legacy transformation plug-ins in the default distribution:

Note: If necessary, legacy plug-ins may be re-installed from earlier DITA-OT distributions, but they are no longer
actively maintained or supported by the core toolkit committers. The source code is available on GitHub for
anyone interested in maintaining the plug-ins for use with future toolkit versions.

Map-first preprocessing

DITA-OT 3.0 provides a map-first preprocessing option as an alternative to
the default preprocess operation. The method, which was introduced in DITA-OT 2.5 as an
experimental feature, has been improved and is ready for use in many production scenarios. Map-first-preprocessing
provides the same functionality as the default preprocess, but takes a different
approach.

Tip: See
Map-first preprocessing for information on how to use (or test) map-first preprocessing, or revert to
the default preprocess target.

New ant.import extension point

A new extension point has been added to make it easier to add new targets to the Ant processing pipeline.

Earlier versions of DITA-OT use the dita.conductor.target.relative to call a wrapper file with
a dummy task that imports the Ant project file. This approach is still supported for backwards compatibility,
but the simpler ant.import approach should be used for all new customizations.